Practical synthetic approaches to several new "purine-like" C-nucleosides are described. These substances are structurally related to several new purine nucleoside antimetabolites synthesized recently in our laboratory, namely the 9-deazapurine C-nucleosides and their thieno(3,2-d)pyrimidine congeners which have exhibited a wide spectrum of useful biological activity. Rationales are offered which are based on: a) the demonstrated anticancer, antitrypanosomal and antileishmanial activity of several members of the 9-deazapurine C-nucleosides and b) their potential use as biochemical probes. It is suggested that the candidates may possess chemotherapeutic properties similar to, or better than those of the lead compounds. "In house" biochemical and biological studies for the proper antitumor evaluations of all target C-nucleosides are described. Other collaborative studies would help evaluate their antiprotozoal properties. Relationships between chemical structures and biological activity should be ascertainable from these investigations.